The world is sometimes slightly slow on the uptake. It takes mental shortcuts, relying on expectations and prejudices to avoid the need to study and think through problems to their solution. So, once you create a mental box for erectile dysfunction drugs, you put the right brands in the box, close it up and forget about it. Particularly when you're young and healthy, you tend to think these drugs are for those old folks who run out of steam as they age. You perhaps think you might get old one day, but you never imagine you'll be needing one of these little pills. You'll never get that old. So it comes as a surprise to discover that these drugs have other uses.

To understand, we need a brief look at the science. The reason for your erectile dysfunction is the muscles in the walls of your arteries stop working as well as they should. Now comes the news flash. You don't just have arteries in your penis. They go everywhere in your body. So scale up what happens to your penis when you take one of these pills. That's a big reaction, isn't it? Now think about your arteries dilating all over your body.

Hey, you're saying, isn't that why people feel faint and their hearts act funny? Yes, you're right. If all your arteries were to dilate, this drops your blood pressure and you might feel faint. That's why you see all these warning about combinations of drugs. If you put two drugs together with the same effect, you get a stronger effect. Put two blood pressure drugs together and it can get a little dangerous.

So, with safety in mind, top athletes are taking little blue pills as part of their training program. Why? Because athletes depend on getting the maximum amount of oxygen to their muscles. If the arteries are dilated, the blood flows fast and the muscles get more oxygen. Performance improves. How do we know this? Well, these drugs are also used to treat altitude sickness. Huh? That's where the oxygen is thin and not enough gets round the body allowing the muscles and the brain to run a little short. Even though you might not have a bottle of oxygen to hand, using these drugs improves the circulation of what little oxygen there is in the air and you can walk down the mountain.

There's little doubt that top athletes are using Viagra. It's one of these open secrets they all joke about because it's slightly embarrassing, but the science says they would all benefit from its use in training. Indeed, the World Anti-Doping Agency takes this so seriously, it has commissioned research and, if the benefits are proved, it will add Viagra to the list of banned substances. If that sounds a little extreme, think of what's at stake. International sport is supposed to be about fair competition. If one group is enhancing their own performances by using drugs, this gives them an unfair advantage. With large financial rewards for those who get to the top of the different sports, there's every incentive to take the pills and aim for the cash rewards.